Transcript Evaporative Emission Control for Gasoline Boat Fuel Systems

Evaporative Emission Control for
Gasoline Boat Fuel Systems
Mike Samulski
U.S. Environmental
Protection Agency
International Boatbuilders’
Exhibition & Conference
October 20, 2005
Evaporative Emissions from Boats
Refueling and spillage
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Diurnal, hot soak, and running loss
Permeation through fuel tank and hoses
EPA’s Role
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Clean Air Act (amended 1990)
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section 213 applies to nonroad engines/equipment
“...greatest degree of emission reduction achievable
through the application of technology...”
consider cost, lead time, safety, energy
Past Efforts
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implemented exhaust emission standards for the
majority of nonroad engines
evaporative emission standards for some applications
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recreational vehicles, Large SI (>25 hp)
originally proposed evaporative emission standards for
marine in August 2002, but have not finalized
Rulemaking Plans
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Scope
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Schedule
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anticipate proposal this spring
final rule ~ 1 year later
Marine Evaporative Emissions
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exhaust and evaporative emissions
gasoline-powered engines/vessels
build on 2002 NPRM
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tank permeation
hose permeation
diurnal breathing losses
Rulemaking Process
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publish “Final
Rulemaking”
FRM
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Implement
publish “Notice of
Proposed Rulemaking”
NPRM
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Public
Comment
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PreProposal
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gather information
meet with stakeholders
lead time
certification
public hearing
written comment period
Tank Permeation Control
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High Density Polyethylene (HDPE)
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Cross-Link PE
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installed fuel tanks (low volume production)
barrier coating, multi-layer roto-molding,
alternative materials, alternative constructions
Fiberglass
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portable, PWC, and some installed fuel tanks
fluorination, sulfonation, Selar, multi-layer,
alternative materials
built-in installed fuel tanks
multi-layer construction
(Metal does not permeate)
Hose Permeation Control
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Multi-layer fuel hose
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barriers used today in non-marine applications
(Teflon, THV, FKM, etc.)
marine barrier hose available as well
can add barriers to current marine constructions
> 95% reduction in permeation possible barrier layer
Evaluating contribution of
vapor versus fuel hose
reinforcement
rubber
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cover
Diurnal Breathing Loss Control
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Portable fuel tanks
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PWC
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currently have manual seal without pressure relief
could use self sealing caps (1 way valve)
already have sealed systems with pressure relief valves
1 psi ~ 50% reduction in-use from an open system
Larger fuel tanks
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carbon canister in vent line
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other technologies include
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> 60% reduction with passive purge
negligible back-pressure
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bladder fuel tanks
active purge canisters
Other Evaporative Emissions
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Venting emissions
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running loss, hot soak, effusion
also reduced somewhat by
diurnal control systems
Refueling emissions
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vapor displacement
spillage
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both air and water pollution issue
could be reduced through fuel system design
configure fill neck for fuel shut-off before overflow
valve to prevent liquid fuel from entering vent line
Questions?
www.epa.gov/otaq/marinesi.htm
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Mike Samulski
[email protected]